FORT WORTH — Spamalot fans may thrill to the cheeky Monty Pythonesque one-liners and clop-clops down long castle corridors that pepper The Nosemaker’s Apprentice: Chronicles of a Medieval Plastic Surgeon at Amphibian Stage Productions.

Theater connoisseurs may appreciate the cleverness of the versatile five-person cast, particularly Brandon Murphy as he transforms himself from a British nosemaker to Austrian and French ones, followed by an over-the-top turn as the Queen of France, with the aid of Derek Whitener’s splendidly sly costumes.

But what Spamalot had and The Nosemaker’s Apprentice lacks is heart. In the end, with the splashiness that distinguishes a big Broadway musical from a small-cast drama aside, the engine that drives Spamalot is “Find Your Grail,” with a message that celebrates differences.

In contrast, the grail of TheNosemaker’s Apprentice is a perfectly proportioned artificial nose that looks and works like the real thing. Nothing to sneeze at, but — check that. Actually it is.

The Nick Jones and Rachel Shukert play is framed as a bedtime story told by a contemporary dad. Trying to make a case for his work as an unlicensed plastic surgeon, the father tells his 8-year-old of a British nosemaker-in-training, Gavin, an apprentice he finds in the Ivanhoe Workhouse for Criminally Impoverished Boys.

Gavin falls for his master’s daughter, Amelia, leaves to study in Austria and ends up working for the Queen, who wants to be made thin and then insists on breast augmentation, horns, a tail and more.

Under the direction of David A. Miller, the play makes a half-hearted stab arguing for reconstructive surgery that restores normalcy vs. the dubious merits of the Queen’s cosmetic obsessions. But the real focus seems to be a romp through the Middle Ages, and that’s what the performers deliver.

John Forkner gives a spirited workout to his half-dozen parts, from knights to students, a female receptionist and a subject of one of Gavin’s butter-filled bust experiments. Skillfully rendered but harder to make appealing, Jay Duffer’s dissolute dad drinks through the bedtime story, with Scott Zenreich’s Gavin as his comically narcissistic alter ego.

Sean Urbantke’s sets add charm, with three horizontal rows of burlap panel curtains offering varying suggestions of depth on a wood-paneled stage. Fred Uebele’s lighting cleverly distracts from Alexandra Lawrence’s swift segues from a side bedroom where she gives a spot-on portrayal of a wide-eyed child to center stage where she inhabits world-weary Amelia.

It’s a witty show that drew many laughs on opening night Thursday and is about as optional as the cosmetic surgery it mocks.